2rus
From Proteopedia
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CRYSTAL STRUCTURE OF THE TERNARY COMPLEX OF RIBULOSE-1,5-BISPHOSPHATE CARBOXYLASE, MG(II), AND ACTIVATOR CO2 AT 2.3-ANGSTROMS RESOLUTION
Overview
The activated ternary complex, enzyme-CO2-Mg(II), of the dimeric, ribulose-1,5-bisphosphate carboxylase/oxygenase from Rhodospirillum rubrum, can be prepared in the same crystal form that was used for the, crystallographic structure determination of the native nonactivated enzyme, (Schneider, G., Branden, C.-I., & Lorimer, G. (1986) J. Mol. Biol. 187, 141-143). The three-dimensional structure of the activated enzyme has been, determined to a nominal resolution of 2.3 A by protein crystallographic, methods. The activator CO2 forms a carbamate with Lys191, located at the, bottom of the funnel-shaped active site. In both subunits, this labile, adduct is stabilized by a Mg(II) ion, bound to the carbamate and the side, chains of Asp193 and Glu194. One solvent molecule was found within the, first coordination sphere of the metal ion. The metal-binding site in, ribulose-1,5-bisphosphate carboxylase consists thus of at least three, protein ligands, all located on loop 2 of the beta/alpha barrel. One, additional metal ligand, the side chain of the conserved Asn111, was, observed close to the Mg(II) ion in the B-subunit. Other structural, differences at the active site between the activated and nonactivated, enzyme are limited to side-chain positions. Nevertheless, it is obvious, that the hydrogen-bonding pattern in the vicinity of the activator site is, completely altered.
About this Structure
2RUS is a Single protein structure of sequence from Rhodospirillum rubrum with MG and FOR as ligands. Active as Ribulose-bisphosphate carboxylase, with EC number 4.1.1.39 Full crystallographic information is available from OCA.
Reference
Crystal structure of the ternary complex of ribulose-1,5-bisphosphate carboxylase, Mg(II), and activator CO2 at 2.3-A resolution., Lundqvist T, Schneider G, Biochemistry. 1991 Jan 29;30(4):904-8. PMID:1899197
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